source = [1, 2, 3, [4, 5, 6], 7]

copy = source.copy()

print(id(source) == id(copy)) # False
print(id(source[0]) == id(copy[0]))  # True


source[3][0] = 'xxxxxxxxxx'

print(copy)  # [1, 2, 3, ['xxxxxxxxxx', 5, 6], 7]